Compared to patients who did not take antipsychotic drugs, users of atypical antipsychotics were 73% more likely to develop the dangerous blood clots. Seroquel use was associated with a nearly threefold adjusted increase in risk among the study population.

The risk to individual patients remained quite small and the findings need to be confirmed by other researchers, study researcher Julia Hippisley-Cox, MD, of the University of Nottingham, tells WebMD.

The study is published in BMJ Online First.

“I would consider this as an important, but modest increase in risk,” she says, adding that the findings add “to the accumulating evidence of adverse health events associated with antipsychotics.”

Antipsychotics Widely Used to Treat Dementia

Antipsychotic drugs are widely prescribed for psychosis and other psychiatric conditions and for non-psychiatric ailments, including nausea and vertigo.

They are among the most widely used drug treatments for agitation in people with Alzheimer’s disease and other forms of dementia, geriatric medicine specialist Rosa Liperoti, MD, MPH, tells WebMD.

This remains the case, even though the FDA has warned their use may be associated with an increased risk of death among the elderly with dementia-related psychosis.